I have a different revision CM9 that works perfectly on this board. Yet this one doesnt. I had another CM9 that produced the same results and I RMA'd it thinking it was defective.
The results are reproducible with both Beta 1 and 2. I've also tried booting with m0n0wall 1.27b just for the heck of it with the same error.</atheros>

I have some cm9s and they all work well. Sounds like defective hardware to me. Can you test this card in another machine? You also might want to try to "mod" the card the way described here: http://forum.pfsense.org/index.php?topic=854.0

ath%d: unable to attach hardware; HAL status %u The Atheros Hardware
Access Layer was unable to configure the hardware as requested. The sta-
tus code is explained in the HAL include file sys/contrib/dev/ath/ah.h.

so your EEPROM on your wlan card has a wrong checksum and so the driver will not accept it. result: no init of the card. May be other driver don't care and the freebsd driver is a little bit sensitive. and may be it really a chance to use the channel tuning utility which will set the value of the country code new in the eeprom and is so nice and will recalculate the checksum. it will be really good if someone has an datasehht of the atheros chipset or a mapping in the eeprom. is it internal?